Many vehicles today are equipped with air circulation systems including automated controls that maintain a set temperature in the passenger compartment of the vehicle. Some vehicles also include hands-free communication systems with Bluetooth connection for operation of a driver's or passenger's cell phone. Some of these systems will reduce the operating speed of the air circulation system blower in order to reduce background noise and allow for better communication over the hands-free system.
This document relates to a windshield defogging system that determines the probability of windshield fogging and then automatically compensates for changes in air circulation system operating parameters and/or changes in environmental conditions so as to provide optimal defogging performance at all times when conditions exist that would otherwise promote windshield fogging.